Apparatus for generating steam



arch 7 H. l.. DOHERTY APPARATUS FOR GENERATING' STEAM Filed March 50, 1921 2 Sheets-Sheet l l l 619 244 March V 1927 H. l.. DOHERTY v I APPAR'IUS` FOR GNERATING STEAM Filed March 30. 1921 2 Sheets-Sheet 2 Patented Mar. 1, 1927. n t t o iran stares Parleur o *rrice L. DOHEISLTY,` OF NEV YORK, N. Y.

APPARATUS FOR GENERATING STEAM- Application filed Iii-arch 3G, 1921. Serial No. 57,1551

ble by the driving otl' of carbonio acid from the water. Included in the first group also is calcium sul iliate which becomes insoluble above 270 Ff Substances belonging to the second group which occur most frequently in boiler-feed waterare sodium'sulphate and salt. l Y

llhis invention relates to apparatus for generating steamv and more particularly to steam generating apparatus of the type comprisingy a boiler and an economizer. l An object of the invention is to provide a boiler constructed and arranged to present a large amount of heat transferring surface in proportion to its size. To this end an important. feature of the invention consists in u boiler comprising a vert cally disposed shell having tire tubes oiening lthrough its upper and lower heads and being. sur ounded by a liue arranged to conduct a heating medium downwardly aboutv the shell f ot' the boiler and into the lower endsoff the lire tubes, through which the heating medium flows upwardly in continuous heat transferring relation to the boiler. In the illustrated construction, the flueA surrounding the boiler is made spiral, thus causing the heating medium to havev a long traverse around the shell of .the boiler and to be c onlined; in spaces of limited cross-section so to cause it to move at a relatively rapid rate. Y A further. object of the invention isto prevent so far. as possible the formation in the boiler of 'leposits or incrusta sides in the provision in a system comprising a boiler and an economizer of means for causing both substances which'are insoluble in hot water. and those. which vare of greater solubility in hot water than in cold water to be precipitated in the economizier. The Siphon which connects the economizer and the boiler is utilized in carrying out the connection with means for introducing feed water into the bottom portion of the economiZer andrfor circulating a'heatingA medium downwardly in heat interchanging relation witlithe water. the economizer. In the use of a steam generating' apparatustlius constructed,l the water in the lower portion Aof the econoinizer is relatively cold, but as it rises in. the economizer it is heated by the com and the hotwater siphoned from the boiler toa point such as to throw down solids insoluble in hot water. The water which flows from the4 boiler to the economizer is rhighly charged withrsoluble matter by reason. of evaporation in the boiler, and a large proportion of thematter held in solution in the boiler water is less soluble in cold water than in hot water. VThen the water from thenboilerv is reduced to the low temperature prevailing in the lower vportion ofthe econo-v mizer, therefore,Y solidmatter is precipitated from it.

The invention will be herein illustrated and described in connection with a gas producer. It is recognized, however. that the invention is not limited in its application to gas producers and that it may be employed Vgenerally for the generation of steam. It fis, therefore, intended that the scope of the Y tions, such as usually attend the operationY ofV boilers due to the 4precipitation of solid matter contained in the feed water. In this aspect of the invention another ofits important fea'- tures resides in the provision of means for continuously removing` precipitatable material from the boiler before ithas been deposited by evaporation. Such means preferably, comprises `a s iphon having its legs immersed in the water in the boiler andthe economiaer respectively. Flow of water is induced through vhe siphon from the boiler to the eeonomizerY by reason ofthetemperature of the water in the boiler being higher than that in the econoinizer.

he greater. portion of the mattervordinarily found'in boiler feed water rmay be divided into two groups; first, matter which is rendered insoluble by heating the water substantially to 2700 F. and hence is precipitated, andv second, matter which is moreV soluble in hot water than in cold water and. is precipitated only lwhen the'solutionj is concentrated `by evaporation ofv the( water. The-first group includes thev carbonates of calcium and'inagnesium which are the cause of so-called temporary hardness. 'ljVhen water containingv such substancesis heated to boiling point, theygare rendered insolurequ-irevdby the claims.

'ln the drawings which illustrate a` preferred embodiment of the invention;

Fig..1 is/aJ longitudinal vertical Vsectional viewofthe boiler and associated parts;

Eig'. Qis a. plan view along the line 2-2 ofFig. l; and

A further feature of the invention relast-mentioned feature of the invention in bined action of the heating medium invention shallV not be'restricted except as renali 5 .Figa 3 is a vertical section through one of lil The tubes lll onen at their the tubes for cleaning the boiler flue, taken on the line 3--3 of Flg. 2.

rlhe steam generating apparatus illustrated in the drawings comprises a boiler mounted in a setting l2 oi suitable retractory material. ln the present clnbodimel'lt of the invention, a single boiler unit: and associati-:d parts, as hereinafter described, are employed, but instead a plurality of suoli units banked together in some suitable manner may be utilized il prel't-a'red. Duplicate parts have not been illustrated since such ,illustration is deemed unnecessary. The boiler l() is ot the so-called vertical return llue lire-tube type and con'iprises tubes .l-lgrouped within a cylindrical shell lll around a central open-ended tube or pipe iS. opposite ends through the upper and lower heads 2t) and 22 ot the shell lli. The pipe 18 serves as a circulation pipe lor the water in the boiler. As shown, the pipe 1S extends from a point a l'ew inches below the water level at the top ol the boiler to within a 'lfew inches ot the bottom or lower head The pipe 18 may, it desired, be constructed in sections, or in the torn'i of a roll of fine mesh screen fabric which may be coated with some suitable paint to till the openings in the `fabric and to reduce friction. The present showing with reference to this pipe is virtually diagram- `matic, and is to be understood as covering all of the `features above specific'L The setting l2 oi the boiler l() is square or rectangular in horizontal section on the outside and circular on the inside, the inner surface being spa fed from the shell of the boiler. `In the illustrated construction the boiler is employed in connection with a gas producer, and one wall of the setting' l2 is equipped with an inlet opening 24 `for the hot gases ol combustion which issue from the producer. The opening 2t is preferably located a short distance below the water line of the boiler and communicates with a conduit connected to the gas producer. `Since the gas producer forms nopart of the invention, it has not been illustrated.

`The space between the boiler 10 and the cylindrical inner wall of the setting l2 contains a partition wall 2G, which nextends spirally around the boiler from the inlet 2a leading iti-om the gas producer to a chamber 3() at the bottom'o't' the setting'. In consequence, there is produced a spiral flue which conducts the hot gases from the producer around the boiler l() to the bottoni chamber 30. The lire tubes le ot' the boiler are open to the chamber and toa chamber 3l lornied in the setting Eat the top of the boiler. "With this construction, the gases from the producer are circulated downwardly in heat transferring relation to the boiler from a point near its top `to its bottoni, and are then caused to flow upwardly through `suitable blow-oil pipe 52..`

the tire tubes lil. The boiler is thus caused to presenta very large heat transferring suriace in proportion to its size. The transiter of heat to the boiler is further enhance-d by the provision ot the spiral flue 32 which causes the gases to have a long traverse around the boiler and contines thern in a space ol relativolj,7 small transverse area thereby increasing the speed of their l'low.

The upper chamber l-l; communicates with a ronduit lt surroaiuliug the steam space or dome ot the boiler. lu this manner, the flue gases are caused to exert as great a superheating ellect as possible on the steam helore they raies on to the ecouomizer. The steam issues i'roni the boiler through a pi Je 37.

relferably, and as shown, the edge oi the spiral wall QG is arranged in substantial contact with the shell fltl oi the boiler. lu order to clean the outer surface ol? the boiler, it is desirable to provide means which may opetate in the spiral flue 3Q. To this end, a tube Elta (Fig. is provided in each corner of the setting 19., and each ot the tubes 38 is iforn'ied with ports at) movable into and out ot alignment with ports Ll-2 in the setting l2 upon rotation ol the tubo. ln order that the tubes 3S may be conveniently rotated, they are provided with handles Lil. The tubes 3S are open at their tops so .as freely to admit an air hose or the like 4 0. lVhen it is desired to clean any portion ol the boiler, one ol the tubes 38 may be turned to align its ports 40 with the ports 42 oi the setting 12, and the air hose may then be employed to direct a blast oi air successively through the ports i0 and et? from the top to the bottoni ot the setting.

To prevent the baking ol. anyT scale-forming substances which may collect on the bottom olE the boiler, the lower head 22 is preierably protected with an under facing 48 oi insulating material ot' soine suitable character.` The facing Li8 tends to stop the agitation ot the water in contact with the head Q2 with the result that an annular zone ol. relatively small circulation is torlned (sce broken lines in Fig. l), starting from about the innermost set oi' ilucs and extending outwardly to the shell 16, the height of the zone increasing until the shell is reached. The bu k ot `the deposited solids collects in this zone. In order that these solids may be readily discharged from the boiler, the lower head 22 is expanded at its edge, as indicated in Fig. 1, so as to produce an annular passage or pocket 50 conununicating with a An annular ring 5-1 is lifted within the rim ot the lower head 22 above the pocket 50 and extends downwardly toward the body ot the head 2:2 so as partially to separate the pocket 50 troni the body portion ol the boiler.

The boiler setting 12 is constructed with a rectangular extension 56 through the up.- per portion o f which the conduit 36 passes. Mounted in the extension 56 adjacent to the boiler 10 is an economizer or feed-water preheater 58 comprising a cylindrical shell 60, upper and lower heads 6 2 rand 64, and a number of tubes 66 opening through the heads 62 and 64. The shell of the economizer 58 is spaced from the adjacent walls of the setting, and hot gases from the conduit 36 pass downwardly through the tubes 66 and about the outer surface of the economizer.

The feed water for the econoniizer 58 is supplied thereto near its bottom by a pipe 68, and water is delivered from the economizer 5 8 to the boiler 10 by a pipe 70 which connects the upper end of the economizer with the pipe 18 in the boiler.

As hereinbefore indicated, feed water, such as is usually available for use in boilers, contains various impurities. These impuritiesmay exist either in a finely divided and suspended state or in solution, and since they are rarely such as are carried off by the steam, they must eventually be deposited either in the economizer or the boiler. In the use of the present invention it is intended that all matter whiehcan be thrown down by heating, such, for example, as the carbonates of lime and magnesium shall be precipitated in the economizer before the feed water reaches the boiler. The mattei' which still remains in solution is carried on by the water to the boiler, and, if not previously removed from it, such matter would be precipitated on the bottom of the boiler as the water was converted into steam.

In accordance with the invention, means is provided for causing the temperature of the water in the econoinizer to be raised to a point such as to throw down the solids which are insoluble in hot water and for removing precipitatable matter from the boiler before it has been deposited in it. The purpose and effect of such means is to reduce greatly the amount of solid matter deposited in the boiler. The illustrated embodiment of such means includes a U-shaped siphon 72, by means of which Va continual flow of water from the bottom of the boiler to that of the economizer is caused to take place. The central section of the siphon 72 enters the boiler through the side at a point above the central pipe 18 but below the level of the water so as to avoid the steam space, and the boiler leg 73 of the siphon extends through and beyond the pipe 18. The leg T3 of the Siphon is provided with a return bend 74 which opens upwardly inside of or directly beneath the central pipe 18 in which the waterfiows downwardly, so as to cause the velocity of circulation of the water in the boiler to tend to increase the flow of water through the siphon from the boiler to the economizer. The other1 leg 75 of the Siphon 72 passes through a manhole or cover 76 on the economizer. In order that the cover 7 6 and the leg 75 may be removed to allow the economizer to be cleaned, the leg is removably coupled to the central section of the Siphon as indicated at 78. The central section of the siphon is preferably enclosed by insulating material 80, in order to prevent the formation of steam in it.

Inasmueh as a large part o f the heat of the iue gases is absorbed by the boiler, the water in the economizer is heated by them to a much less degree than that in the boiler. Consequently, by reason of the expansion o f water when heated, the water in the boiler leg 7 3 of the siphon is lighter than that in the ecenoinizer leg. It follows, therefore, that flow of water is induced through the Siphon 72 from the boiler` l0 to the Veconoinizer 58. The. greater' weight ofl the water in the economiz-er leg of the Siphon as comparedwith that in the boiler leg is due to the transfer of heat from the water in the siphon to the water in the economizer. Accordingly, the more rapidly heat is transferred from the siphon to the water in the economizer, the more rapid will be the iiow of water through the siphon.V In order to increase the flow of water, the economiuei' leg 75 is constructed so as to cause rapid in'- terchange of heat between the water in the siphon and that in the economizer. To this end the pipe leading from the boiler is connected adjacent to the top of the economizer with a header 82 from which depends a number of small tubes 841 which provide a large amount of heat interchanging surface. The combined capacity of the tubes 84 is Vconsiderably greater 'than that of the Siphon 72, so that a relatively slow flow through'the tubes will suffice to induce a considerable fiow through the Siphon. Moreover, the slow discharge of Ywater from the lower ends ofthe tubes 84 prevents disturbalice of deposits of solid matter on the bottom of the economizer 58. 'Y

In order to precipitate to the greatest pos sible degree matter such as the carbonates of lime and magnesium which may be rendered insoluble by heating, the water must be raised substantially to the bolling point before it leaves the economizer. YThen the producer is operated at a low rate, however, the heat of the gases from it may be absorbed by theboiler to an extent such that the gases alonewill not heat the water in. the economizer to the point required. In such a ease, the water conducted from the boiler' to the economizer by the siphon will supply sufficient additional heat to'effeet the desired precipitation.

The manner in which heat is transmitted to the water in the economizer and the manl ner of introducingr Water into the eeonornizaer are such as to produce a strati fication ot the Water into what may be termed heat zones. A hot layer of water at the top of the eeonoluizer and a cold layer at the bottom are particularly well dciined.

then the producer is operated at a` high rate` thus causingI the heating gares to he supplied to the boiler in larger quantity and at a higher telnlnrature, the water in the boiler ie evaiiorated more rapidly. .increase in the rate ot efaporation induces a .more rapid circulation ot the water, which in turn causes an increased .flow oit' water through the siphon 72. l\loreover, when the producer is operated at an increased rate, the heating gases pase to the cconoini'fzcr at a higher temperature. Consequently, when water in supplied more rapidly to the boiler troni the econolnizer to replace that which is cvapo rated, an increased amount ol heat ie inn parted to the water in the ecoiunnimr so to heat the increased amount ol water passn ing through the cconoinizer to the required degree.

The arrangement ol the parts is such that the water at the top of the eeonoiniz-:cr is brought substantially to the tmnneraurc at which the water boils under the preesure obtaining in the boiler. The heat transter rc quired to be et'rected through the Shell and the tire tubes ot the boiler is thereby reduced to a minimum, thus enabling steam to be generated in the boiler at a very rapid rate and with high efficiency.

Boilers are generally operated under a predetermined gage pressure, which causes the water to boil at a temperature considerably above 2700. In the ordinary use of the apparatus ot this invention, the water in the boiler 10 and eeonoinizer 58 .is heated above 270C thus cauaing any calcium sulphate which may be present in f the ieed water to be precipitated. in the eeononiizer. Il calcium sulphate does, however, enter the boiler, it eventually separates.; troni the water in the forni of a light, tlocculent precipitate which is held in suspension by the rapidly circulating water 'tor a considerable time. A considerable part ot it is, therefore, carried back to the econornizer through the siphon 72.

As previouslyT indicated, the Water in the boiler beooniel highly charged n'itli mat-ter in solution by reafion et evapcnation ot the water. The continual tiow ot highly charged water from the boiler through the siphon72 and its replacement by i'resh Water from the econoniizer 58 counteracts the ten d cncy ot' evaporation to produce saturation and hence reduces the precipitation ot solid matter in the. boiler. A large portion ot the matter contained in the boiler is ol lese solubility in cold Water than in hot water. Conthe use ot the siphon T2 results in the prevc-ipitatimi in thc economia/,cr o't'j the bulk ott the matter contained in the water, including both that Vwhich is rendered .iir-toluble by heating and that which is more soluble in hot water than in cold water. ln the use ol' the aiiparatus ot this inventioil, therefore.J the econoinizer alone rcduiree trequent blow-- ing-otl or cleaning, since only a sinall part ot the nlattcr contained in the ieod water is de4 positcd in the boiler. Not only is it advantageous; that only one member ot the system 'requires` cleaning instead oi both, but Solid nuttelniay bc removed much more readily 'troni the eronomiir than from the boiler since the bottoni ot the economir/.er not hot enough to cause the precipitated mattei' to halte on it or to torni in a hard crust.

he lower head oi the economizer 5b? is I n'eicrably insulated in a manner similar to the head :22 ot: the boiler.l and the bottoni ot the econon'iizer is provided with a circun'itercntial pocket 85 connected with a blow-oil' pipe SG. The soiids precipitated in the econoniizer may be removed periodically or continuously by blowing oil through the pipe Sti.

its shown. the econoniizer 58 is supported on spaced shelves 88 projecting inwardly :trom the netting. Gases outside ot the econ olnizer pass through the spaces between the ahelves SS and, together lwith the gases from the tubes (it), enter an opening 90 leading to a ilue Ul (Fig.

The c induit 36 above the econolnizer eonininnicates directly with a recuperator 92 provided "within the extension 56 o't the Setting, eo that a portion ot the gases entering the conduit it is caufied to pass throiurh the economiser tubes (iti. while the remaining portion in an aniount determined by a gate 93 in the conduit Siti enters the recuperator Where it passes through a nest of thin metal tubes 94. which are set in upper and lower direc heads Siti and 98. The econoinizer and r u'fupcrator thus operate in parallel on the trafics which have passed the boiler. The recupcrator tiues are utilized to heat the air deiivin'ed to the producer, the air entering the reruperator through a conduit 100 and cirenlatingI between the lines 94. The Warm air issues from the top ot the recuperator thriiugh a conduit lOQ and is conducted to the producer, preferably through underground tlues. The gases, on passing` through lill) Ail) feras/i4 the tubes 94 enter the chamber 10i beneath the recuperator, and then'pass through an opening/106 to a flue 108;r y y y f Having fully described the invention, what is claimed is: A Y

l. In 'an apparatus of the class described, an upright fire tube boiler and a furnace therefor, al feed water preheater, an inverted U-shape'd conduit having one inthe preheatei'and the other leg in t-he boiler, the vlast-"named leg having its lowery end turned upwardly, said end being located near the bottoni of the boiler and substantially in the airis thereof, an open-ended tube extending upwardly from said upturned end and in vertical alignment therewith the top of the tube terminating short of the water line in the boiler, said boiler and furnace being` so constructed and arranged as to produce a downward circulation of water within said openV ended tube, and a feed water pipe connecting the preheater with the upper portion of said tube. h

In an apparatus ofthe class described, an upright boiler and a furnace therefor, a central upright open tube within thc boiler, said furnace and boiler being so constructed and arranged as to produce a downward circulation of water in said open-ended tube, a supply pipe connected to the upper portion of said open tube and an eXit pipe having an upwardly directed return bend disposed within the central open pipe.

3. in an apparatus of the class described, a boiler, a furnace for said boiler, a central upright open tube within the boiler, said furnace and boiler being so constructed and arranged as to produce a downward circulation of water within said open-ended tube, an economizer, a water supply pipe leading to the lower portion of the said econoinizer, a feed water pipe leading from the upper portion of the economizer to the upper por- .tion of said tube, and an exit pipe leading from the lower portion of the boiler to the lower portion of the economizer, said exit pipe having an upwardly directed opening near the bottom of the boiler and in alignment with the bore of said, central tube.

4:. In an apparatus of the class described, a boiler', a furnace for said boiler, a central upright open tube within the boiler,'said furnace and boiler being so constructed and arranged as to produce a downward circulation of water Vwithin said open-ended tube, an econoinizer, a water Supply pipe leading to the lower portion of the econoniizer, a second water supply pipe leading from the upper portion of the economizer to the upper portion of said tube, a siphon tube leading from the lower portion of the boiler to the lower portion of the economizer, a sediment draw-oft pipe connected to the bottom of the said boiler, and a second sediment draw-olf pipe connected to the bottom of trally in the boiler, said boiler. and furnace being so constructed and arranged as to produce a downward circulation of water in. said open-ended tube, said tube having `its upper end disposed below the water line and its lower end spaced from the lower head, a'siphon having one leg extending through said tube, and its other leg disposed within thev econoinizer, the last-nan'ied leg being composed of small pipes extending at their free end into the bottom portion of the economizer and the siphon leg within the tube having its4 bottom terminal upwardly directed and arranged in the path of t-he watei' flowing downward through said openended tube.

6. The combination, with a boiler, an econoniizer, and a furnace for said boiler,

said boiler and said economizer each comprising upper and lower heads connected by a set of substantially vertical lire tubes, of an open-ended tube arranged centrally in the boiler and having its upper end disposed below the water line and its lower end spaced from the lower head, said boiler and furnace being so constructed and arranged as to produce a down-flow of waterv in said open-ended tube, a pipe arranged below the water levels in the boiler and economizer and Iserving to connect the economizer with said tube, blow-off pipes connected to the said boiler and economizer, and an inverted U- shaped conduit having one leg within the boiler and having its other leg within the econoniizer and extending at its free end into the bottoni portion of the econoinizer the leg within the boiler havingk its lower open terminal turned upwardly adjacent the bottoin opening in said open-ended tube and arranged in the path of th-e water flowing downwardly therethrough.

7. The combination with a boiler and an econoinizer of Vmeans for supplying feed water to the boiler from the econoinizer and an inverted U-shaped conduit arranged to conduct water from the boiler to the economizer, said conduit having one of its legs in the boiler and its oth-er leg in the econ'- oinizer, the leg in the econoinizer comprising a plurality of pipes of larger combined heat interchanging surface and capacity than the main body of the conduit in order to induce a relatively large flow of water through it and to reduce the velocity of flow llO of the writer in tbe eeononlizer leg ol the eondult, the lower termin-nl of the len' withu 1n the boiler having an upturned end loeeted substantially in the exis o'. the boiler,

und menus :for directing n strenni of fluid into smid upturned end.

S. The eolnbinntion with n boiler, :in eeonomizer, and :i urnnee 'lor Suid boiler, Said boiler und Suid eeononlizer eneh eoin- )risingr upper :1nd lower bende connected by n set of eubetnntially vertienl lire-tubes, of an upright openended tube arranged eentrally in the boiler :1nd having its upper end disposed below the Waiter line and ite lower en( spaced fronrthe lower heed. Seid boiler and :furnace being so construct-ed :1nd nrrzinged es to cause n downward flow el *eter in seid opeirended tube and a Siphon having one leg extending through said tube and terminating at its :tree end in an u werdly directed return bend 'disposed Wit 1- in seid tube und having its other leg (lisposzed within the eeonoinizer, the last-named .leg being; composed ol small )ipes extending :1t their free ende into the I botton'i portion o the eeoneniizer, sind a feed water pipe leading from the eeonomizer to the upper end of seid tube. i

In testimony Wh lreo'f I affix my signature HENRY L. DOHERTY. 

